1. Field of the Invention
The present invention relates to the art of electrical connectors with fastening structures, and more particularly to an electrical connector with a fastening structure provided for mechanically and electrically connecting a chip module to a printed circuit board (PCB).
2. Description of the Prior Art
Electrical connectors are widely used in the connector industry for electrically connecting a chip module to a printed circuit board (PCB) in personal computer. Conventionally, an LGA electrical connector mainly comprises an insulative housing, a multiplicity of terminals received therein, a metal stiffener surrounded the insulative housing, a load plate pivotably attached to one end of the metal stiffener for pressing the chip module and a lever pivotably attached to an opposite end of the metal stiffener for buttoning the load plate on the metal stiffener. The LGA electrical connector further includes four washers assembled on the four corners of the metal stiffener.
The stiffener is substantially rectangular and comprises a base and a front sidewall extending upwardly from the base for securing the load plate and a back sidewall also extending upwardly from the base for connecting the lever and a pair of lateral sides upwardly extending from the opposed lateral edges of the base and located between the front sidewall and the back sidewall. The stiffener further defines four circular through holes at the corner of the base for retaining the four washers.
Each washer includes a main portion defining a circular center hole in the middle thereof and a multiplicity of snapped portions extending at a same direction from the inner side of the center hole and a groove formed between each two snapped portions.
When the electrical connector is assembled on the printed circuit board, the stiffener is always need some fastening members such as bolts to be located on the printed circuit board (PCB). And each said through hole at the four corners of the stiffener is not only for receiving the fastening member but also for securing the washer. The snapped portions of washers are received in and retained to said through hole of the stiffener. Thus the diameter of the through hole is need to be larger and the diameter of a head of the bolt becomes much larger correspondingly. If not, the bolt may loose its locating function. So the diameter of the bolt in conventional electrical connector has a limitation on smallest diameter, so the choice of bolt becomes narrow.
Thus, there is a need to provide an improved electrical connector that overcomes the above-mentioned problems.